ZPL 2.1 라이선스에 copyleft 조항이 있다고 봐야할까요?

또 ZPL 라이선스를 따르는 파일 사용시 의무사항은 무엇인가요?

Zope Public License (ZPL) Version 2.1

A copyright notice accompanies this license document that identifies the

copyright holders.

This license has been certified as open source. It has also been designated as

GPL compatible by the Free Software Foundation (FSF).

Redistribution and use in source and binary forms, with or without

modification, are permitted provided that the following conditions are met:

1. Redistributions in source code must retain the accompanying copyright

notice, this list of conditions, and the following disclaimer.

2. Redistributions in binary form must reproduce the accompanying copyright

notice, this list of conditions, and the following disclaimer in the

documentation and/or other materials provided with the distribution.

3. Names of the copyright holders must not be used to endorse or promote

products derived from this software without prior written permission from the

copyright holders.

4. The right to distribute this software or to use it for any purpose does not

give you the right to use Servicemarks (sm) or Trademarks (tm) of the

copyright

holders. Use of them is covered by separate agreement with the copyright

holders.

5. If any files are modified, you must cause the modified files to carry

prominent notices stating that you changed the files and the date of any

change.

Disclaimer

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY EXPRESSED

OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO

EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,

INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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License 관리자

안녕하세요

공개소프트웨어 라이선스 관리자입니다.

문의주신 내용 답변드립니다.

ZPL-2.1 라이선스는 퍼미시브 계열의 라이선스입니다.

BSD-3 라이선스에 타 상표권 사용 금지, 수정사항 고지 조항이 추가된 라이선스로 보입니다.

ZPL 라이선스를 따르는 파일 사용 시 배포하실 때 수정사항을 포함한 고지의무를 준수하셔야 합니다.

감사합니다.

※ 법적 분쟁 발생시 본 답변은 법률적 해석이나 논리로 활용될 수 없습니다.